1. Field of the Invention
The present invention generally relates to an IC card processing apparatus and, more particularly, to an IC card processing apparatus having a function for detecting and protecting dishonest utilization using a switch means when a read/write process is to be performed to an IC card having a memory circuit and the like formed therein.
2. Description of the Related Art
As is well known, an IC card, unlike a magnetic recording card, electrically stores various kinds of information in a memory, and is formed such that the information is exchanged between the IC card and an external apparatus connected to the card through terminals arranged on the outer surface portion of the card.
FIG. 9 shows an example of a conventionally known IC card 1. An integrated circuit (not shown) including a memory and the like are incorporated in the IC card 1. A plurality of external terminals 2 connected to the internal integrated circuit are respectively arranged at predetermined positions near the leading end on one surface 1a of the card 1.
When such an IC card does not electrically exchange predetermined information with the external apparatus through the external terminals, information unique to a card holder, transaction information, or the like cannot be recognized. For this reason, the IC card does not allow dishonest utilization easier than a magnetic card, and the contents of the IC card are not changed by an external magnetic force. Therefore, IC cards have been used in place of magnetic cards.
An IC card processing apparatus for reading/writing information from/in an IC card receives an IC card inserted from a card insertion port until a predetermined portion including at least the external terminal portion of the IC card is inserted into the apparatus, and contact terminals are brought into contact with the external terminals of the card in the apparatus, respectively, thereby receiving and transmitting information through the contact terminals.
However, such an IC card processing apparatus may not protect dishonest utilization by a wrong card 3 shown in FIG. 10 and an information decoding apparatus (not shown). More specifically, the wrong card 3 has the same shape as that of a proper IC card and external terminals 4 respectively arranged at the same positions as those of the proper IC card, and conductive lines 5 extend from at least some of the external terminals. This wrong card 3 is inserted into the IC card processing apparatus to bring the external terminals 4 into contact with the contact terminals in the apparatus, and the information decoding apparatus is connected to the distal ends of the conductive lines 5, thereby decoding the format, data, or the like of information exchange performed between the IC card processing apparatus and the IC card. On the basis of the decoding result, information may be exchanged between the wrong card and the IC card processing apparatus in the same manner as that of the proper card.
In a card processing apparatus which completely receives an IC card into the apparatus, the presence of the conductive lines is certainly mechanically or optically detected to prevent such dishonest utilization. In a card processing apparatus in which a card is manually inserted and discharged, the trailing portion of the card is exposed from a card insertion port. For this reason, when conductive lines are drawn from this exposed portion, the presence of the conductive lines cannot be mechanically or optically detected.
As a prior art for solving this problem, as in an IC card processing apparatus 10 shown in FIG. 11, electrode plates 13 and 14 are arranged between a card insertion port 11 and contact terminals 12 to oppose an inserted card, and a static capacitance determination circuit 15 for checking whether the capacitances between the contact terminals 12 and the electrode plates 13 and 14 are larger than a predetermined value is arranged. When the wrong card 3 is inserted to a position where the external terminals 4 are brought into contact with the contact terminals 12, increases in static capacitances between the conductive lines of the wrong card 3 and the electrode plates 13 and 14 are detected to determine that the received card is a wrong card.
However, in the prior art in which the conductive lines of the wrong card are detected by the static capacitances between the electrode plates and the conductive lines, the static capacitances considerably change depending on the distances between the electrode plates and the conductive lines or the diameters of the conductive lines. When very thin conductive lines are located at a position distant from the electrode plates, the static capacitances therebetween are very small, and it is very difficult to certainly determine the presence/absence of the conductive lines on the basis of the very small changes in static capacitances.
In the above prior art, there are problems that a conductive plate such as an electrode plate must be attached to a card storage unit to satisfy severe conditions, and the shape of the card storage unit is strictly limited. In addition, for example, when a wrong card cut shorter than a proper IC card, a piece of paper, or the like is inserted into the card processing apparatus, since this wrong card, piece of paper, or the like cannot be discharged from the card storage unit due to the presence of the plate, a card jam is caused.